NFA based formal verification of automatic payroll processing system

With the passage of time the needs of an organization grow, therefore, the operational work and responsibilities are also grown. That is why there is a need of hiring more employees. Calculating salaries of many employees requires a lot of work and chances of occurring errors also increase. Automatic Payroll Processing System (APPS) simplifies the work by reducing errors and saving the time. In this paper, we present a Non-Deterministic Finite Automata (NFA) based on formal model that is an effective approach for describing behavior of systems. Our algorithm presented in this paper depicts the processing of APPS and then it is verifies the system using formal methods which are mathematical statements providing reliable and accurate systems. VDM-SL is used for validating and verification of the system which provides a detailed level examination.